It tells us that most possibly that the iPhone could be announced at this...
Most thought this was going to be about OSX and Lion only...
Actually, iOS 6 was completely expected, not a surprise at all.
Apple typically releases the new version of iOS to developers a few months before the phone launches. Apple announced iOS 5 at WWDC in June last year and released the iPhone 4S in October, so don't be disappointed if they don't announce the new iPhone. That's just standard practice for Apple. All these iPhone leaks are interesting though, I wouldn't mind seeing the phone come early.